A Signature That Sits on Top of the Varnish
A local collector brings you a small oil on panel, 38 × 30 cm, said to be a 17th-century portrait of a bearded man. The panel has a vertical join; the craquelure is fine and even across the face but wider and lifting along the join. The surface has a yellowed varnish and a dark, glossy signature in the lower left that sits visibly on top of the varnish layer. Under ultraviolet light the varnish fluoresces milky green while the signature stays dark. A spot test on the signature finds zinc white, while the sky and flesh contain lead white and earth pigments only. The frame is 19th-century, and the back of the panel carries a paper label from a Maltese dealer dated 1928. The owner is convinced it is by a named Italian master and wants a written statement to that effect for a sale.
1. Assess the evidence for and against the attribution.
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Weigh the evidence by how much it can actually carry.
Against a 17th-century signature (strong):
- Zinc white in the signature only. Zinc white came into use as a artists' pigment in the 19th century; its presence in the inscription and absence from the painting is close to decisive. The signature cannot be contemporary with a 17th-century picture.
- Signature on top of the varnish, dark under UV. Original inscriptions sit under the varnish and are usually masked by it; this one was applied after a varnish layer existed.
Neutral (consistent with age, but not proof of it):
- Fine, even craquelure and a joined panel - normal for a 17th-century panel, and equally normal for a 19th-century one made in that manner.
- The 1928 dealer label proves only that the picture was in Valletta in 1928. It is provenance, not attribution.
- The 19th-century frame tells you nothing about the painting's date and may simply be a reframe.
The live possibility is a 17th-century painting - or a later copy - carrying a 19th-century added signature. Both are common. Nothing in the evidence reaches the named master.
2. What do you write, and what wording do you avoid?
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Write: a condition and examination note, not an attribution. Something on the order of: 'Italian School, 17th century (?) - the painting is of a period consistent with the 17th century, but the signature is a later addition in a pigment not available before the 19th century, and no attribution to a named artist can be supported on present evidence.' State your own qualification and the limits of what you did.
Avoid:
- 'By [named master]' - nothing supports it.
- 'Attributed to' without saying by whom and on what basis; in the trade it implies a considered scholarly consensus.
- 'School of' used loosely when you mean 'circle of' or 'after'.
- Any valuation. You are not an accredited valuer, and a figure in writing for a sale is a liability.
Recommend further work: infrared reflectography for underdrawing, X-radiography, dendrochronology of the panel, binder analysis of the signature, and comparison with documented works. Then add a clear caveat that the lifting paint along the join should be consolidated by a conservator before the panel travels for any of it.
3. What does the owner need to understand before any sale?
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Three things, in this order.
- The signature is a liability, not an asset. An added 19th-century signature on a painting sold as 17th-century is exactly what a buyer's due diligence will find. It is better to disclose it now, with your note, than to have it discovered later - that is the difference between a disappointing valuation and a dispute.
- Condition affects both value and handling. Cupping and lifting along the join means further loss is likely with movement, transport or RH swings. Consolidation is a small cost now and a large one after flakes have dropped.
- Do not let anyone 'clean off' the signature. It is evidence. Removing it destroys the very thing that dates the inscription and would itself be an undocumented intervention.
Also flag: no valuation from you, an independent examination by a specialist if a sale is serious, and - because the frame is 19th-century and probably original to the picture's later history - keep it; do not reframe to make the picture look older than it is. A cautious written note protects the owner, the buyer and you.